Dynamics and Regulation of the Maltose ABC Transporter of Escherichia coli/Salmonella

ATP-binding cassette (ABC) transporters are membrane proteins that mediate the uptake or export of an enormous variety of substrates at the expense of ATP. ABC transporters share a common structural organization comprising two transmembrane domains that form the translocation pore and two nucleotide-binding domains that hydrolyse ATP. The maltose transporter of E. coli/Salmonella has served as the model for canonical ABC import systems which require an additional component, a substrate-specific binding protein for function. Based on a plethora of genetic, biochemical and structural data we propose to investigate the dynamics of the system in detail. To this end, we will combine site-specific chemical cross-linking with electron paramagnetic resonance spectroscopy to identify individual steps of the transport cycle. The results, together with molecular modelling will eventually lead to a complete picture of the transporter s motional changes and thus to the understanding of the transport mechanism at the molecular level. Furthermore, we will address by the same techniques completed by fluorescence-based technology (FP-FRET, FCS), the physiologically relevant question of the mechanism by which the glucose transporter component, EIIAGlc, inhibits the maltose transporter in a process termed inducer exclusion .

Principal Investigators
Schneider, Erwin Prof. Dr. rer. nat. (Details) (Physiology of Microorganisms)

Duration of Project
Start date: 08/2010
End date: 04/2014

Grote, M., Bordignon, E., Polyhach, Y., Jeschke, G., Steinhoff, H.-J., and Schneider, E. (2008) A comparative EPR study of the nucleotide-binding domains catalytic cycle in the assembled maltose ABC-importer. Biophys. J., 95, 2924-2938.
Daus, M. L., Grote, M., Müller, P., Doebber, M., Herrmann, A., Steinhoff, H.-J. Dassa, E., and Schneider, E. (2007) ATP-driven MalK dimer closure and re-opening and conformational changes of the EAA motifs are crucial for function of the maltose ATP-binding cassette transporter (MalFGK2). J. Biol. Chem. 282, 22387-22369.
Daus, M.L., Berendt, S., Wuttge, S., and Schneider, E. (2007) Maltose binding protein (MalE) interacts with periplasmic loops P2 and P1, respectively, of the MalFG subunits of the maltose ATP-binding cassette transporter (MalFGK2) from Escherichia coli / Salmonella during the transport cycle. Mol. Microbiol. 66, 1107-1122.
Daus ML, Grote M, and Schneider E (2009) The MalF P2 loop of the ATP-binding cassette transporter MalFGK2 from Escherichia coli and Salmonella enterica serovar typhimurium interacts with maltose binding protein (MalE) throughout the catalytic cycle. J. Bacteriol. 191, 754-761.
Jacso T, Grote M, Daus ML, Schmieder P, Keller S, Schneider E, and Reif B (2009) The periplasmic loop P2 of the MalF subunit of the maltose ATP binding cassette transporter is sufficient to bind the maltose binding protein MalE. Biochemistry 48, 2216-2225.
Daus, M.L., Landmesser, H., Schlosser, A., Müller, P., Herrmann, A., and Schneider, E. (2006) ATP induces conformational changes of periplasmic loop regions of the maltose ATP-binding cassette transporter. J. Biol. Chem. 281, 3856-3865.
Grote, M., Polyhach, Y., Jeschke, G., Steinhoff, H.-J., Schneider, E., and Bordignon, E. (2009) Transmembrane signaling in the maltose ABC transporter MALFGK2-E: The periplasmic MALF-P2 loop communicates substrate availability to the ATP-bound MalK dimer. J. Biol. Chem. 284, 17521-17526.
Blüschke, B., Volkmer-Engert, R., and Schneider, E. (2006) Topography of the surface of the signal transducing protein EIIAGlc that interacts with the MalK subunits of the maltose ATP-binding cassette transporter (MalFGK2) of Salmonella typhimurium. J. Biol. Chem. 281, 12833-12840.

Last updated on 2020-25-11 at 15:04